Alternating-current motor.



V. A. FYNN.

ALTERNATING CURRENT MOTOR.

APPLICATION FILED MAR. a, 1909.

v Patented May 3, 1910.

VALERE ALFRED FYNN, OF LONDON, ENGLAND.

ALTEBNATING-CURRENT MOTOR.

Specification of Letters Patent.

Patented May 3, 1910.

Original application filed December 19, 1906, Serial No. 348,659.Divided and this application filed March 6, 1909; Serial No. 481,762.

To all whom 'it may concern: 4

Be it known that I, VALERE ALFRED FYNN, a subject of the King ofEngland,

' cember it), 1906. i

'My invention relates to alternating "current commutator motors of thesinglephase induction type the induced and commuted winding of which isclosed over brushes and along more than one axis per pole pair.

The objects of this invention are to make it possibleto operate suchmotors from a single-phase supply and at any desired constant speedquite independently of the periodicity ot' the supply and of the numberof poles of the motor, to make it possible to rationally vary or adjustthis speed, and to improve their commutation.

According to this inventionl adjust the speed of a self-excitedalternate current motor of the said type to any desired and practicallyconstant speed dittering from the synchronous, or I vary its speed atwillby conductivelyintroducing into the exciting circuit a regulatingE.- M. F. practically in phase quadrature with that impressed on themain inducing winding; this quadrature E. M. F. can be derived from aphase converter. this machine by varying the magnitude of thetransformer flux due to the main stator inducing winding. magnitude ofthis fiux also causes the speed of the motor to vary when the quadratureregulating E. M. F. is not zero. I improve the power factor of thismachine in the manner already disclosed by me in my United States PatentNo. 777,198; 2'. c. by including in the working circuit of the rotor anE. M. F. approximately in phase quadrature with that impressed on themain stator winding or by including in the exciting circuit of the rotoran E. M. F; approximately in phase with the E. M. F. impressedon themain stator winding.

Referring to-the accompanying drawing I improve the commutation of- Thevariation of the.

which diagrammatically illustrates a twopole motor made in accordancewith my invention where the quadrature E, M. F. is derived from a phaseconverter, 1, 2 are the mains and they are connected to the main statorinducing winding 3; the volts per turn of 3 can be regulated as shown at4, thus regulating the magnitude of the transformer flux. The inducedmember is provided with a commuted winding 5 and is short-circuitedalong the axis of 3 byway of the working brushes 6, 7. It is assumedthat only a single phase supply is available, the quadrature regulatingE. M. F. included in the exciting circuit is therefore derived from aphase converter 13. Any kind of phase converter can be used, one of thesquirrehcage (19) induction type has been shown for the sake ofsimplicity. One winding 16 of the phase converter can be regulated at 18and is connected to the mains 1, 9.; the other winding in which an E. M.F. in quadrature with that impressed on 16 or 3 is induced is includedin the exciting circuit of the motor to be regulated. The commutedwinding 5 here does duty as exciting circuit along an axis preferablydisplaced by 180/91. degrees, where the letter a stands for the numberof poles of the motor, from that of 3. The exciting brushos 8, 9 aretherefore connected to 60 which represents the source of the quadratureregulating E. M. F. Because brush 8 is connected to an intermediatepoint 63 of 60 then 62 not only serves to vary the magnitude but alsothe direction of the regulating E. M. F. derived from 60.

Having fully described my invention,

what'I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an alternating current motor, the combination with an inducingmember provided with a main inducing winding, of an induced membershort-circuited along an axis approximately coinciding with that of themain inducing winding, and meansfor introducing into said induced memberalong another axis an E. M. F. approximately in phase quadrature to thatimpressed on the main inducing winding.

2. In an alternating current motor, the combination with an inducingmember pro vided with a main inducing winding, of an induced memberprovided with a commuted winding short-circuited'along an axis api themain inducing winding, and a phase converter connected in seriesrelation with the induced member along another axis.

at. In an alternating current motor the combination with a stationarymember provided with a main inducing winding, of an induced memberprovided with a commuted winding short-circuited along an axisapproximately coinciding with that of the main inducing winding, and aphase converter connected in series relation with the induced memberalong another axis.

5. In an alternating current motor, the combination With an inducingmember provided with a main inducing winding, of an induced membershort-circuited along an axis approximately coinciding with that of themain inducing Winding, means for introducing into said induced memberalong another axis an E. M. F. approximately in phase quadrature to thatimpressed on the main inducing winding, and means for varying the voltsper turn in said main inducing winding.

In witness whereof I have hereunto set my hand and aflixcd my seal inthe presence of the two subscribing Witnesses.

VALERE ALFRED FYNN. [1,. 8.]

Witnesses:

W. A. ALEXANDER, E. E. HUF MAN.

